The human eye provides vision by transmitting light through a clear outer portion, the cornea, and the eye focuses the image onto the retina by way of a crystalline lens. The image quality depends on many optical factors including the size and shape of the eye, and the transparency of the cornea and lens.
When age or disease causes the lens to become less transparent, vision deteriorates because of the reduced light which can be transmitted to the retina. This medical condition or deficiency of the lens of the eye is medically known as a cataract. To treat this medical condition the lens is typically surgically removed and replaced by an artificial intraocular lens (IOL).
In the United States, the majority of the cataractous lenses are surgically removed using a procedure called phacoemulsification. During this procedure, an opening, or capsulorhexis, approximately 4 mm in diameter is made in the anterior capsule of the crystalline lens, and a small diameter phacoemulsification cutting tip is inserted into the cataractous lens and the simultaneous ultrasonic motion and aspiration suction removes the cataractous lens without damage to the surrounding capsule. An artificial lens is then implanted to replace the natural lens; however, this lens typically, in the past, has been what is called a monofocal lens with just one focal length. Having only one focal length requires one to use reading glasses because that patient can no longer accommodate naturally to magnify his/her near vision.
Examples of implantable artificial intraocular lenses include various design configurations. Generally, the lenses are attached in some manner within the eye, usually by sutures to the iris, or some other supporting means, such as arms, or haptics, extending from the optical lens portion of the intraocular lens.
U.S. Pat. No. 4,053,953 (Flom et al.) describes an artificial intraocular lens for the aphakic eye. The lens is secured in the posterior chamber by a system of posts that protrude through the iris attached to retaining rings.
U.S. Pat. No. 6,015,435 (Valunin et al.) describes a self-centering phakic intraocular lens inserted into the posterior chamber lens for the correction of myopia, hyperopia, astigmatism, and presbyopia. Haptic bodies are attached to the optical body and extend outward from tangent points at the edge of the lens in at least two generally opposite directions. Protruding surfaces protrude into pupil such that the iris interferes slightly with lens movement and provides the centering force to the keep lens in place.
U.S. Pat. No. 4,710,195 (Giovinazzo) describes a posterior chamber lens, particularly adapted for patients with glaucoma and cataracts. Two haptics are connected to the optic body at its edge. The haptics are offset from the other by 180 degrees and extend circumferentially around the edge of the optic portion. The haptics end in enlarged “blocking segments”.
U.S. Pat. No. 4,676,792 (Praeger) describes an artificial intraocular lens device implantable in the anterior chamber of the eye (in front of the iris) for treating myopia. The optic body has three or four “J” shaped haptics that terminate with solid footplates to anchor the lens. In one embodiment, haptics are positioned circumferentially around the edge of the optic body approximately 90 degrees apart. The haptics are grouped in pairs so that each pair is oriented such that the respective curved surfaces of solid footplates face each other.
U.S. Pat. No. 5,133,747 (Feaster) describes an intraocular lens device that is partially or completely within the anterior capsular surface of the human crystalline lens. In one embodiment, the optic body has asymmetrical haptics extending outwardly from opposite sides of the periphery of the optic body. In one embodiment, “J” shaped haptics extend from the periphery of the optic body in a manner that encircles the optic body. In another configuration, the haptics extend tangentially away from body, then reverse direction, giving the device an overall “S” shape with the lens at the center portion of the S. The device is secured in place with an adhesive.
U.S. Pat. No. 5,928,282 (Nigam) describes a refractive intraocular lens for implantation into the anterior chamber. The lens body has elongated, ovoid-disc shaped haptics extending from its peripheral edge.
U.S. Pat. No. 4,994,080 (Shepard) describes optical lens devices having an optical body with multiple perforations and two J shaped haptics that terminate in footplates.
U.S. Pat. No. 6,083,261 (Callahan et al.) describes an intraocular lens having crossed haptics for implantation into either phakic or aphakic eye.
U.S. Pat. No. 4,285,072 (Marcher et al.) describes closed loop haptics on an intraocular lens. When positioned in the eye; the circular arched haptics without footplates extend rearward from the optic body, then angle sideways to allow the arch to rest in the angle to keep the lens in place. This design proved to be physiologically unsuitable for use.
U.S. Pat. No. 5,275,623 (Sarfarzi) describes an elliptical accommodative intraocular lens having dual lens fixed optics.
WIPO Publication No. 00/66037 (Glick, et al.) describes a dual fixed optic intraocular lens.
WO 01/34067 A1 (Bandhauer, et al) describes an accommodating intraocular lens system with specific flexibility characteristics to facilitate axial displacement of a positive fixed optic portion.
U.S. Pat. Nos. 6,197,059; 5,674,282; 5,496,366; and 5,476,514 (all by Cummings) describe an accommodating intraocular lens having a central optic and two flexible haptics that allow forward and backward fixed optic motion in reaction to ciliary muscle movement.
Similar designs are described in U.S. Pat. No. 6,302,911 B1 (Hanna), U.S. Pat. Nos. 6,261,321 B1 and 6,241,777 B1 (both to Kellan).
According to U.S. Pat. Nos. 6,197,059, 5,674,282, 5,496,366 and 5,476,514, the eye must be paralyzed for one to two weeks in order for the capsular fibrosis to entrap the lens thereby provide for a rigid association between this type of lens and the capsular bag.
U.S. Pat. Pub. No. 2002/0002404 A1 (Sarfarazi) describes an open chamber, elliptical, accommodating intraocular lens system.
U.S. Pat. No. 2005/0119741 A1 (Esch et al.) describes a fluid filled/piston driven accommodating intraocular deformable optic lens.
U.S. Pat. Pub. No. 2003/0147046 A1 (Shadduck) describes an intraocular lens capable to create highly localized surface corrections in the lens to correct higher order aberrations.
U.S. Pat. Pub. No. 2003/0060878 A1 (Shadduck) describes an intraocular lens capable of cooperating with an external RF or light source to expose a charge to a charge-carrying fluid within the interior chamber.
This and all other referenced patents and applications are incorporated herein by reference in their entirety. Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
As the human lens ages, it becomes harder to see, usually well before becoming cataractous, and is less able to return to its relaxed, smaller optical radius shape with a smaller equatorial diameter that is required for near vision as the ciliary muscle tightens or contracts when the brain activates this muscle to magnify an image that one desires to see up close. This lens hardening over several years makes it impossible for the lens to deform as needed to focus on near objects. This medical condition is known as presbyopia. Presbyopia affects nearly all adults over the age of 45 to 50. To treat presbyopia, the lens could be surgical removed and replaced by an artificial Accommodating Intraocular Lens (AIOL).
Therefore, a need exists for an intraocular lens that has accommodating effects for the patient. Additionally, a need exists for an intraocular lens that may flex to allow for natural physical and neural eye anatomy.